Hydroquinones are known to be useful in color diffusion transfer photographic elements. Examples of such compounds are described in U.S. Pat. Nos. 3,537,849, 3,253,915, 3,039,869, 3,192,044 and 3,411,904. The photographic elements described therein are color diffusion transfer photographic elements using a dye developing agent as a dye image forming material. More specifically, they are color diffusion transfer photographic elements wherein the dye image forming material in a reduced state (i.e., the dye developing agent itself) is movable in an alkaline medium, but is mordanted in the image receiving component to form a color image and an oxidized dye developing agent which are immovable. The function of these hydroquinones in such photographic elements is to assist the development of silver halide by the dye developing agent.
In addition to the above-described color diffusion transfer photographic elements used, it is known to use a dye releasing redox compound capable of releasing a diffusible dye as a result of a redox reaction with an oxidation product of the developing agent caused by development of silver halide as a dye image forming material. It has been described in Research Disclosure, No. 15162, page 79 (published in November, 1976) that, in such color diffusion transfer photographic elements, certain kinds of hydroquinones hinder cross-oxidation of the oxidation product of the developing agent and the dye releasing redox compound to control gradation.
In the present specification, a compound having the above-described function of controlling gradation is called a "competitive developing agent".
A further description in Research Disclosure, No. 15162 indicates that hydroquinone, methylhydroquinone and t-butylhydroquinone are particularly effective as competitive developing agents. The use of hydroquinone, methylhydroquinone and t-butylhydroquinone have an effect on controlling gradation. However, sufficient control of the gradation cannot be achieved utilizing these compounds.
A color diffusion transfer photographic elements comprising (a) a photosensitive component containing at least one photosensitive silver halide emulsion layer combined with a dye-releasing redox compound, (b) a dye image receiving component and (c) an alkaline processing composition component, wherein at least one of the above described components (a), (b) and (c) contains a compound represented by the following general formula ##STR2## where R represents a substituted or unsubstituted alkyl group having from 1 to 18 carbon atoms, are described in U.S. Ser. No. 193,495, filed on Oct. 3, 1980 and now U.S. Pat. No. 4,429,031.